German Patent No. 30 50 102 describes a sorting plant which has an endless chain of carts which circulates on a closed rail that forms a loop. Each cart of this chain has a receptacle that can be swiveled about on a slanted axis from its horizontal starting position into two dumping positions. Several loading stations at which the piece goods are loaded onto the receptacles and several target stations are arranged along the loop. One of the target stations is assigned to the cart onto which the piece goods are loaded at the loading station. Once the cart reaches the target station, a horizontal rail is transversely displaced, so that it presses against the outer perimeter of a rotating disk arranged on the cart. This results in the disk being turned, thus tilting the receptacle into one of its two dumping positions, so that the piece goods are unloaded at the target station.
This plant has proven itself very well in practical application, particularly in those instances where the size of the piece goods fluctuates only slightly. However, if the size of the various piece goods fluctuates significantly, certain difficulties exist with regard to accuracy at the target stations since the receptacles that are tilted about the slanted axes accelerate the piece goods differently, toward the side, depending on the position of their center of gravity. The speed of the chain of carts must thus be reduced if significantly fluctuating sizes of piece goods are transported, which in turn also limits the capacity of the plant.
DE-OS 26 58 517 describes another sorting plant. In this particular instance, the carrying receptacles of the carts can be selectively swiveled about one of two horizontal axes that are laterally displaced relative to each other. In the starting position the receptacle is retracted into correspondingly offset bearing shells by two tension springs. This application also mentions that one individual package could be placed onto two carrying receptacles. However, this is only possible if the rail has a linear extension between the loading station and the target station since the unavoidable relative movement of adjacent receptacles on curves or on inclines would lead to an uncontrollable displacement of the package and thus to disruptions in the activity of the plant because the position of the center of gravity and the condition of the packages would vary significantly. In addition to this, the unloading of a package at the target station largely depends on the position of the center of gravity and thus, according to this suggestion, becomes relatively inaccurate.